Beginning of the Liturgical Year

Among the ancient Mediterranean cultures, it was common to begin a new year in the autumn, with the end of the previous year's harvest. The civil year of the Byzantine (Eastern Roman) Empire began in September, and September 1, the first day of the civil year, also called the "Indiction", became the first day of the Church's year as well. The First Ecumenical Council (325) decreed that the Church’s year should begin on September 1.  

The lunar month corresponding to September on the Jewish calendar was the beginning of the civil year (cf Exodus 12:2); it was at this time that our Lord Jesus went into the synagogue at Nazareth and read the words of the prophet Isaiah, “The Spirit of the Lord is upon me...to proclaim ‘the acceptable year of the Lord.’ (Isaiah 61:1-2; Luke 4: 16-21).